I am currently using WiX Toolset to build my installer. This tool is very nice but recently I encountered a problem. When I installed my program with .exe, then upgrade it with .msi, there is a double-entry in Add/Remove Program. Is there anyway to prevent the installer add double entry? Thanks!
It's not clear from your post if you have followed the rules for a major upgrade, such as use the same UpgradeCode, new ProductCode and PackageCode, increment ProductVersion in the first three fields, have upgrade logic in place in the MSI (such as major upgrade element). You'd need to supply your WiX source for these in the old and upgrade builds to see the differences. A verbose log would also help, installing the MSI with a command line that includes /l*vx [path to log file]
If those rules have been followed, the main reason for failure to upgrade is the one was per user and the other is per machine (or vice versa). One context will not upgrade the other. If this is the case the log will have an entry somewhere with FindRelatedProducts referring to an installed product in another context.
All this also assumes that the original install you did was MSI-based underneath the exe. If it was not, and it was some other install software that is not using an MSI file then there is no such thing as an automatic upgrade. You'd need to find some none-MSI way to uninstall the older product. A typical way is to find the UninstallString in the registry for that product and run it. Depending on the software used, that command can be parsed to add a silent option.